Thermodynamics Applied to Geothermal Power Plants: Case Study—Unit 5, Cerro Prieto, Baja California Mexico

2011 ◽  
Author(s):  
He´ctor Enrique Campbell Rami´rez ◽  
Gisela Montero Alpirez ◽  
Margarita Gil Samaniego Ramos ◽  
Benjamin Valdez Salas
Keyword(s):  
Power Plants ◽  
Cooling Tower ◽  
Cooling Water ◽  
Normal Operation ◽  
Vacuum System ◽  
Cooling Water Temperature ◽  
Exit Temperature ◽  
Higher Temperature ◽  
Geothermal Power ◽  
Cerro Prieto

Cerro Prieto Geothermal Power Plant has a capacity of 720 MW. The earliest 5 units are 23 years old, and unit 5 from Cerro Prieto Uno was restored in 2008. This paper presents a thermodynamic analysis on the effects that has the increase of non condensable gases content in geothermal steam. Results show that the cooling water temperature will rise due to the energy entering the system with the water flow of the new vacuum system that feeds the condenser. Normal operation would be limited and there exists a risk of not sustaining the condenser’s pressure. The new vacuum system, should extract from the condenser a flow 4 times larger, requiring 27% more steam at a higher pressure, as well as 4.5 times the quantity of cooling water. At this condition, the water returning to the condenser is 4.3 times larger than the original at a higher temperature, increasing in 218% the associated energy. A thermal behavior model was obtained for the cooling tower. In the most likely scenario the cooling tower exit temperature will be higher than the required, and to maintain the equilibrium it will be necessary to lower the condenser thermal load by reducing the steam flow to the turbine and accordingly, the power delivered.

A Kind of Energy Saving Method Based on Improving Turbine Condenser Vacuum

2011 ◽  
Vol 347-353 ◽  
pp. 3116-3119
Author(s):  
Jing Hong Yao
Keyword(s):  
Heat Transfer ◽  
Energy Saving ◽  
Cooling Water ◽  
Economic Indicator ◽  
Heat Transfer Analysis ◽  
Vacuum System ◽  
Cooling Water Temperature ◽  
Heat Transfer Efficiency ◽  
Turbine Condenser ◽  
Production Practice

Vacuum is an important economic indicator of influencing turbine load and thermal efficiency. And heat transfer efficiency affects the level of vacuum directly. From the point of heat transfer analysis, combining with the production practice in a power plant, this paper proposes a method of improving heat transfer effectiveness and the condenser exchanging condition. Through the method of reducing the heat load of condenser, improving the tightness of the vacuum system, cleaning the heat surface and reducing the cooling water temperature, we improve the vacuum and reach the aim of energy saving.

Thermodynamic simulation and mathematical model for single and double flash cycles of Cerro Prieto geothermal power plants

Geothermics ◽  
2020 ◽  
Vol 83 ◽  
pp. 101713 ◽  
Author(s):  
Emilio Hernández Martínez ◽  
M.C. Patricia Avitia Carlos ◽  
José Isaac Cisneros Solís ◽  
M.C. María del Carmen Prieto Avalos
Keyword(s):  
Mathematical Model ◽  
Power Plants ◽  
Thermodynamic Simulation ◽  
Geothermal Power ◽  
Cerro Prieto ◽  
Double Flash

scholarly journals Analysis of the evaporative towers cooling system of a coal-fired power plant

2012 ◽  
Vol 16 (suppl. 2) ◽  
pp. 375-385 ◽  
Author(s):  
Mirjana Lakovic ◽  
Slobodan Lakovic ◽  
Milos Banjac
Keyword(s):  
Energy Efficiency ◽  
Power Plant ◽  
Theoretical Analysis ◽  
Power Plants ◽  
Cooling Tower ◽  
Cooling System ◽  
Low Cost ◽  
Cooling Water ◽  
Energy Efficiency Improvement ◽  
Condensing Pressure

The paper presents a theoretical analysis of the cooling system of a 110 MW coal-fired power plant located in central Serbia, where eight evaporative towers cool down the plant. An updated research on the evaporative tower cooling system has been carried out to show the theoretical analysis of the tower heat and mass balance, taking into account the sensible and latent heat exchanged during the processes which occur inside these towers. Power plants which are using wet cooling towers for cooling condenser cooling water have higher design temperature of cooling water, thus the designed condensing pressure is higher compared to plants with a once-through cooling system. Daily and seasonal changes further deteriorate energy efficiency of these plants, so it can be concluded that these plants have up to 5% less efficiency compared to systems with once-through cooling. The whole analysis permitted to evaluate the optimal conditions, as far as the operation of the towers is concerned, and to suggest an improvement of the plant. Since plant energy efficiency improvement has become a quite common issue today, the evaluation of the cooling system operation was conducted under the hypothesis of an increase in the plant overall energy efficiency due to low cost improvement in cooling tower system.

scholarly journals Experimental Aspects in the Vibration-Based Condition Monitoring of Large Hydrogenerators

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Geraldo Carvalho Brito Junior ◽  
Roberto Dalledone Machado ◽  
Anselmo Chaves Neto ◽  
Mateus Feiertag Martini
Keyword(s):  
Condition Monitoring ◽  
Accurate Determination ◽  
Cooling Water ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Normal Operation ◽  
Steady State Condition ◽  
Dimensional Changes ◽  
Cooling Water Temperature ◽  
Theoretical Predictions

Based on experimental observations on a set of twenty 700 MW hydrogenerators, compiled from several technical reports issued over the last three decades and collected from the reprocessing of the vibration signals recorded during the last commissioning tests, this paper shows that the accurate determination of the journal bearings operating conditions may be a difficult task. It shows that the outsize bearing brackets of large hydrogenerators are subject to substantial dimensional changes caused by external agents, like the generator electromagnetic field and the bearing cooling water temperature. It also shows that the shaft eccentricity of a journal bearing of a healthy large hydrogenerator, operating in steady-state condition, may experience unpredictable, sudden, and significant changes without apparent reasons. Some of these phenomena are reproduced in ordinary commissioning tests or may be noticed even during normal operation, while others are rarely observed or are only detected through special tests. These phenomena modify journal bearings stiffness and damping, changing the hydrogenerator dynamics, creating discrepancies between theoretical predictions and experimental measurements, and making damage detection and diagnostics difficult. Therefore, these phenomena must be analyzed and considered in the application of vibration-based condition monitoring to these rotating machines.

scholarly journals ANALISIS KEGAGALAN OPERASI COOLING TOWER FAN UNIT 2B PLTU ASAM ASAM

JTAM ROTARY ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 65
Author(s):  
Andhika Bayu Oktavianto ◽  
Mastiadi Tamjidillah
Keyword(s):  
Power Plant ◽  
Preventive Maintenance ◽  
Power Plants ◽  
Cooling Tower ◽  
Cooling Water ◽  
Working Fluid ◽  
Steam Power ◽  
Steam Power Plant ◽  
Plant Uses ◽  
Engineering Team

Salah satu pembangkit listrik di Indonesia adalah pembangkit listrik Asam Asam yang terletak di dekat mulut tambang batubara. Setiap pembangkit listrik membutuhkan sejumlah besar air sebagai fluida kerja atau sebagai air pendingin. Pembangkit Listrik Tenaga Uap Asam Asam Batubara menggunakan air sungai sebagai air pendingin dengan mesin pendingin sebagai mesinnya. Pada bulan September 2017, menara pendingin unit 2B dari PLTU Asam Asam Batubara mengalami kegagalan operasi karena spacer rusak dan membuat PLTU Asam Asam Batubara mengalami penurunan dan kerugian lainnya. Tim teknik mendiagnosis kasus tersebut karena ketidakselarasan. Berdasarkan uraian akar penyebab masalah, ada tiga masalah utama yang mungkin terjadi yaitu: misalignment, unbalance, dan rotasi gearbox berat. Misalignment adalah pemicu utama untuk serangkaian masalah yang menyebabkan kegagalan operasi menara pendingin. Maka perlu mempelajari masalah utama yang menyebabkan kegagalan operasi menara pendingin untuk ditindaklanjuti dengan pemeliharaan preventif sesuai dengan kondisi saat ini untuk mencegah kegagalan yang serupa di unit 2B dan unit serupa lainnya. One of the power plants in Indonesia is the Asam Asam power plant located near the mouth of the coal mine. Each power plant requires large amounts of water as a working fluid or as a cooling water. Asam Asam Coal Fired Steam Power Plant uses river water as a cooling water with the cooling towers as its engine. In September 2017, the cooling tower unit 2B of Asam Asam Coal Fired Steam Power Plant experienced an operation failure because of the spacer was broken and made the Asam Asam Coal Fired Steam Power Plant to experience derating and other losses. The engineering team diagnoses the case due to misalignment. Based on the description of the root causes of the problem, there are three main problems that might occur namely : misalignment, unbalance, and heavy gearbox rotation. Misalignment is the main trigger for a series of problems causing failure of cooling tower operations. Then it is necessary to study the main problems causing the failure of the cooling tower operation to be followed up with preventive maintenance in accordance with the current conditions to prevent similar failures in unit 2B and other similar units.

Modeling Power Generation Water Usage

2015 ◽  
Author(s):  
Jaron J. Peck ◽  
Amanda D. Smith
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Power Output ◽  
Power Plants ◽  
Cooling Tower ◽  
Cooling Water ◽  
Rankine Cycle ◽  
Closed Circuit ◽  
Cooling Systems ◽  
Temperature Range

Climate change can have a large effect on thermoelectric power generation. Typical thermoelectric power plants rely on water to cool steam in the condenser in order to produce electricity. Increasing global temperatures can increase average water temperatures as well as decrease the amount of water available for cooling due to evaporation. It is important to know how these parameters can affect power generation and efficiency of power systems, especially when assessing the water needs of a plant for a desired power output and whether a site can fulfill those needs. This paper explains the development of a model that shows how power and efficiency are affected due to changing water temperature and water availability for plants operating on a Rankine cycle. Both a general model of the simple Rankine cycle as well as modifications for regeneration and feedwater heating are presented. Power plants are analyzed for two different types of cooling systems: once-through cooling and closed circuit cooling with a cooling tower. Generally, rising temperatures in cooling water have been found to lower power generation and efficiency. Here, we present a method for quantifying power output and efficiency reductions due to changes in cooling water flow rates or water temperatures. Using specified plant parameters, such as boiler temperature and pressure, power and efficiency are modeled over a 5°C temperature range of inlet cooling water. It was found that over this temperature range, power decrease ranged from 2–3.5% for once through cooling systems, depending on the power system, and 0.7% for plants with closed circuit cooling. This shows that once-through systems are more vulnerable to changing temperatures than cooling tower systems. The model is also applied to Carbon Plant, a coal fired power plant in Utah that withdraws water from the Price River, to show how power and efficiency change as the temperature of the water changes using USGS data obtained for the Price River. The model can be applied to other thermoelectric power stations, whether actual or proposed, to investigate the effects of water conditions on projected power output and plant efficiency.

Application of Optimal Preview Control to Power Plant Cooling Systems

1979 ◽  
Vol 101 (2) ◽  
pp. 162-171 ◽  
Author(s):  
D. R. Gunewardana ◽  
M. Tomizuka ◽  
D. M. Auslander
Keyword(s):  
Power Plants ◽  
Cooling Tower ◽  
Dynamic Control ◽  
Cooling Water ◽  
Control Policy ◽  
Substantial Improvement ◽  
Ambient Conditions ◽  
Preview Control ◽  
Cooling Systems ◽  
Control Scheme

This paper deals with the application of dynamic control to cooling systems of power plants. The operation of heat dispersal systems with control can result in a saving of power and cooling water. The performance of all cooling systems depends, mainly, upon the ambient conditions and the heat load to be dissipated. Hence, a control scheme that makes use of information obtained by previewing the weather and load conditions, i.e., preview control, is ideally suited for this problem. An iterative procedure is presented for determining the optimal preview control policy for a dynamical system whose dynamics vary depending upon the mode of operation that the controller selects. The algorithm is applied to two types of cooling systems: one consisting of a spray pond and a natural draft wet cooling tower, and the other consisting of a spray pond and a dry cooling tower. The preview control scheme is shown to be a substantial improvement over the uncontrolled case.

Optimum Condenser Cooling Water Temperature Rise in Power Plants

2003 ◽  
Author(s):  
Ram Srinivasan
Keyword(s):  
Power Plant ◽  
Water Temperature ◽  
Steam Turbine ◽  
Temperature Rise ◽  
Power Plants ◽  
Cooling Water ◽  
Design Parameters ◽  
Plant Design ◽  
Optimum Temperature ◽  
Cooling Water Temperature

The concept of optimum cooling water temperature rise in a power plant has been introduced in this study as that which corresponds to the highest possible net plant output. Every power plant having a steam turbine exhausting to a water-cooled condenser has a unique optimum cooling water temperature rise. This optimum temperature rise may not be the minimum possible as often inadvertently assumed by power plant designers. This optimum temperature rise is a strong function of the steam turbine exhaust parameters. The author has developed correlations, which will help determine the optimum temperature rise using easily available power plant design parameters. This paper will discuss the details behind this method and show the thermal and financial advantages of designing a plant with this concept. A proper understanding of this concept will enable power plant designers to economically and efficiently size the condenser cooling water system.

Sign in / Sign up

Export Citation Format

Share Document